Automation with voice assistant

I am trying to make an automation to play an artist using voice assistant, but cannot get it working… I am sure i made errors, but still don’t know where.
The automation is the following:

- id: Artisti
  alias: Artisti Vari
  description: Artisti Vari
  variables:
    artista: "{{ artist }}"  
  triggers:
  - trigger: conversation
    command:
    - "{{ artist }}"
  conditions: []
  actions:
  - set_conversation_response: Riproduco songs di "{{ trigger.slots.artist }}"
  - action: media_player.shuffle_set
    target:
      entity_id: media_player.wiim_pro_airplay
    data:
      shuffle: true
  - action: music_assistant.play_media
    target:
      entity_id: media_player.wiim_pro_airplay
    data:
      media_id: "{{ trigger.slots.artist }}"
      media_type: artist
      enqueue: replace
  mode: single

Please let me know where i am wrong…

Wrong indentation in trigger and actions?

Examples from the docs:

automation:
  triggers:
    - trigger: time_pattern
      minutes: 5
      # our second trigger is the sunset
    - trigger: sun
      event: sunset
  actions:
    - action: "{{ notification_action }}"
      data:
        message: "Beautiful sunset!"
    - delay: 0:35
    - action: notify.notify
      data:
        message: "Oh wow you really missed something great."

Hmmm, i don’t think that’s the error. The indentation is correct as it is created by HA itself…